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Geometry 3-1 Parallel Lines and Angles

- Parallel Lines- lines that never intersect
- Symbol
- Perpendicular Lines- lines that intersect and

make right angles - Symbol -
- Parallel Planes- planes that do not intersect
- Skew lines- lines that are not coplanar, are not

parallel, and do not intersect.

Examples

Identify each of the following.

a. a pair of parallel segments

BF EJ

b. a pair of perpendicular segments

BF - FJ

c. a pair of skew segments

BF and CD

Vocabulary

- Transversal A line that intersects two lines at

different points.

Transversal line

Exterior

Interior

Exterior

Vocabulary

- Corresponding angles the same angle location but

for a different intersection.

congruent

B

A

C

D

B

A

C

D

Vocabulary

- Alternate Interior Angles opposite sides of the

transversal and between the parallel lines.

congruent

B

A

A

B

Vocabulary

- Alternate Exterior Angles opposite sides of the

transversal and outside the parallel lines.

congruent

A

B

A

B

Vocabulary

- Same-Side Interior same side of the transversal

and between parallel lines.

supplementary

A

B

A

B

Vocabulary

- Same-Side Exterior Angles same side of the

transversal and outside the parallel lines.

supplementary

B

A

A

B

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